Codex Desktop Stop/checkpoint can lose original thread closeout bubble after continuation

Upstream Bug Report - Codex Desktop Stop/Checkpoint UI Loss

Summary

Pressing Stop can preserve the continuation checkpoint but remove the last visible assistant closeout bubble from the original thread.

Steps to Reproduce

1. Start a long-running Codex Desktop task in a thread.
2. While the assistant is still responding or wrapping up, press Stop.
3. Let Codex create the continuation/checkpoint thread.
4. Reopen the original thread.
5. The continuation thread proves the Stop event happened, but the original thread no longer shows the last visible assistant closeout bubble.

Environment

• macOS
• Codex Desktop 26.406.31014 (1395)
• app bundle path: /Applications/Codex.app

Expected

• The original thread keeps the last visible assistant closeout bubble and the turn closes cleanly.

Actual

• The continuation thread contains an auto-checkpoint for the same session, but reopening the original thread no longer shows the assistant closeout bubble the operator saw before switching away.

Additional Context

• This report is based on one historical source thread with operator-corroborated visible content loss after Stop/continuation.
• A broader local stop-capture dataset shows that raw open-turn-after-stop events are common in proof/probe interruptions and should not be read as bug frequency by themselves.
• The continuation checkpoint survived; the missing piece is the original thread's visible closeout bubble.